#define str(s)       #s
#define xstr(s)      str(s)
#define debug(s, t) printf("x" # s "= %d, x" # t "= %s", \
                                 x ## s, x ## t)
#define INCFILE(n)  vers ## n /* from previous #include example */
#define glue(a, b)  a ## b
#define xglue(a, b) glue(a, b)
#define HIGHLOW      "hello"
#define LOW          LOW ", world"
debug(1, 2);
fputs(str(strncmp("abc\0d", "abc", '\4') /* this goes away */
        == 0) str(: @\n), s);
#include xstr(INCFILE(2).h)
glue(HIGH, LOW);
xglue(HIGH, LOW)

